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Steroids Dec 2021Vecuronium bromide (Piperidinium, 1-[(2β,3α,5α,16β,17β)-3,17-bis(acetyloxy)-2-(1-piperidinyl)androstan-16-yl]-1-methyl-, bromide; Norcuron®) has been extensively...
Vecuronium bromide (Piperidinium, 1-[(2β,3α,5α,16β,17β)-3,17-bis(acetyloxy)-2-(1-piperidinyl)androstan-16-yl]-1-methyl-, bromide; Norcuron®) has been extensively used in anesthesiology practice as neuromuscular blocking agent since its launch on the market in 1982. However, a detailed crystallographic and NMR analysis of its advanced synthetic intermediates is still lacking. Hence, with the aim of filling this literature gap, vecuronium bromide was prepared starting from the commercially available 3β-hydroxy-5α-androstan-17-one (epiandrosterone), implementing some modifications to a traditional synthetic procedure. A careful NMR study allowed the complete assignment of the H, C, and N NMR signals of vecuronium bromide and its synthetic intermediates. The structural and stereochemical characterization of 2β,16β-bispiperidino-5α-androstane-3α,17β-diol, the first advanced synthetic intermediate carrying all the stereocenters in the final configuration, was described by means of single-crystal X-ray diffraction and Hirshfeld surface analysis, allowing a detailed conformational investigation.
Topics: Crystallography, X-Ray; Magnetic Resonance Spectroscopy; Models, Molecular; Molecular Structure; Neuromuscular Blocking Agents; Vecuronium Bromide
PubMed: 34655596
DOI: 10.1016/j.steroids.2021.108928 -
Insects Nov 2021Recently, spotted wing Drosophila, , is globally prevalent and causes agricultural losses to many fruits. To export Korean strawberry, methyl bromide fumigation is...
Recently, spotted wing Drosophila, , is globally prevalent and causes agricultural losses to many fruits. To export Korean strawberry, methyl bromide fumigation is required to remove infestations, but Korean strawberry farmers are worried about fruit damage because methyl bromide can cause phytotoxicity on fresh commodities. In this report, we assessed the efficacy and phytotoxicity of single and successive application of methyl bromide and cold treatment on an export variety of strawberry to reduce fruit damage. The currently recommended dosage of methyl bromide, 40 g/m for 3 h at 18 °C, was enough to control all stages of without phytotoxicity. A dosage of 20 g/m of methyl bromide treatment for 3 h, followed by 1 d of cold (0 °C) treatment, showed 100% mortality in all growth stages of without fruit damage. Successive application of methyl bromide and cold treatment shows potential as a method of decreasing phytotoxicity and reducing the use of methyl bromide for environmental considerations.
PubMed: 34821790
DOI: 10.3390/insects12110990 -
Journal of Korean Medical Science Dec 2010The purpose of this article was to provide a literature review of occupational neurological disorders and related research in Korea, focusing on chemical hazards. We... (Review)
Review
The purpose of this article was to provide a literature review of occupational neurological disorders and related research in Korea, focusing on chemical hazards. We reviewed occupational neurological disorders investigated by the Occupational Safety and Health Research Institute of Korean Occupational Safety and Health Agency between 1992 and 2009, categorizing them as neurological disorders of the central nervous system (CNS), of the peripheral nervous system (PNS) or as neurodegenerative disorders. We also examined peer-reviewed journal articles related to neurotoxicology, published from 1984 to 2009. Outbreaks of occupational neurological disorder of the CNS due to inorganic mercury and carbon disulfide poisoning had helped prompt the development of the occupational safety and health system of Korea. Other major neurological disorders of the CNS included methyl bromide intoxication and chronic toxic encephalopathy. Most of the PNS disorders were n-hexane-induced peripheral neuritis, reported from the electronics industry. Reports of manganese-induced Parkinsonism resulted in the introduction of neuroimaging techniques to occupational medicine. Since the late 1990s, the direction of research has been moving toward degenerative disorder and early effect of neurotoxicity. To understand the early effects of neurotoxic chemicals in the preclinical stage, more follow-up studies of a longer duration are necessary.
Topics: Adolescent; Adult; Central Nervous System Diseases; Female; Humans; Male; Middle Aged; Nervous System Diseases; Neurodegenerative Diseases; Neurotoxicity Syndromes; Occupational Diseases; Parkinsonian Disorders; Peripheral Nervous System Diseases; Republic of Korea
PubMed: 21258587
DOI: 10.3346/jkms.2010.25.S.S26 -
Environmental Monitoring and Assessment Jun 2021Methyl bromide (MB) is a highly toxic and ozone-depleting substance and should be replaced. Worker exposure to high MB concentrations during fumigation has been...
Methyl bromide (MB) is a highly toxic and ozone-depleting substance and should be replaced. Worker exposure to high MB concentrations during fumigation has been previously reported. However, variations in MB concentration as a function of distance from fumigated objects or of time after degassing have not been reported so far. In this study, air samples were collected at various distances from fumigated objects (oranges, wood in containers, and wood in tarpaulin) during injection and degassing and analyzed via gas chromatography according to the Occupational Safety and Health Agency method. In addition, MB concentrations were directly measured over time using a gas detector during degassing. Non-linear regression analysis of the logarithmically transformed data indicated a clear decrease in MB concentration with distance as well as time. Non-linear regression models were constructed to describe the decrease in MB concentration with distance from the objects and with time during degassing (P < 0.05 for all models). The results of this study could aid in establishing appropriate safety guidelines, and hence, in preventing risks related to MB exposure.
Topics: Environmental Monitoring; Fumigation; Hydrocarbons, Brominated; Quarantine
PubMed: 34105044
DOI: 10.1007/s10661-021-09154-3 -
Environmental Health Perspectives Jun 2013Methyl bromide, a fungicide often used in strawberry cultivation, is of concern for residents who live near agricultural applications because of its toxicity and...
BACKGROUND
Methyl bromide, a fungicide often used in strawberry cultivation, is of concern for residents who live near agricultural applications because of its toxicity and potential for drift. Little is known about the effects of methyl bromide exposure during pregnancy.
OBJECTIVE
We investigated the relationship between residential proximity to methyl bromide use and birth outcomes.
METHODS
Participants were from the CHAMACOS (Center for the Health Assessment of Mothers and Children of Salinas) study (n = 442), a longitudinal cohort study examining the health effects of environmental exposures on pregnant women and their children in an agricultural community in northern California. Using data from the California Pesticide Use Reporting system, we employed a geographic information system to estimate the amount of methyl bromide applied within 5 km of a woman's residence during pregnancy. Multiple linear regression models were used to estimate associations between trimester-specific proximity to use and birth weight, length, head circumference, and gestational age.
RESULTS
High methyl bromide use (vs. no use) within 5 km of the home during the second trimester was negatively associated with birth weight (β = -113.1 g; CI: -218.1, -8.1), birth length (β = -0.85 cm; CI: -1.44, -0.27), and head circumference (β = -0.33 cm; CI: -0.67, 0.01). These outcomes were also associated with moderate methyl bromide use during the second trimester. Negative associations with fetal growth parameters were stronger when larger (5 km and 8 km) versus smaller (1 km and 3 km) buffer zones were used to estimate exposure.
CONCLUSIONS
Residential proximity to methyl bromide use during the second trimester was associated with markers of restricted fetal growth in our study.
Topics: Adult; Agriculture; Birth Weight; California; Female; Fetal Development; Fetus; Humans; Hydrocarbons, Brominated; Linear Models; Maternal Exposure; Pregnancy
PubMed: 23603811
DOI: 10.1289/ehp.1205682 -
Journal of Nematology Oct 1987The efficacy of methyl bromide for control ofMeloidogyne arenaria and to increase yields of 'Florunner' peanut (Arachis hypogaea) was studied in a field at the Wiregrass...
The efficacy of methyl bromide for control ofMeloidogyne arenaria and to increase yields of 'Florunner' peanut (Arachis hypogaea) was studied in a field at the Wiregrass Substation near Headland, Alabama. Methyl bromide was applied in the row at a depth of 35 cm using a subsoiler-bedder 2 weeks before planting at rates of 0, 34, 50, 67, 101, and 118 kg a.i./ha. Methyl bromide treatments of 67 kg a.i./ha or higher resulted in significant (P = 0.05) yield increases similar to those obtained in the same experiment with at-plant applications of aldicarb (2.2 kg a.i./ha), EDB (1.55 ml a.i./m row), or 1,3-D (5.10 ml a.i./m row). The relation between yield (Y) and methyl bromide rate (x) was described (R(2) = 0.97**) by the exponential function: Y = 2,302.963eb, where b = (- 1.901 - ln x)(2)/169.482. M. arenaria juvenile populations in soil in mid-August were too low to permit establishment of a relation between application rate of methyl bromide and size of the population.
PubMed: 19290276
DOI: No ID Found -
PloS One 2015Methyl bromide (MB) and other alternatives were evaluated for suppression of Fusarium spp., Phytophthora spp., and Meloidogyne spp. and their influence on soil microbial...
Methyl bromide (MB) and other alternatives were evaluated for suppression of Fusarium spp., Phytophthora spp., and Meloidogyne spp. and their influence on soil microbial communities. Both Fusarium spp. and Phytophthora spp. were significantly reduced by the MB (30.74 mg kg-1), methyl iodide (MI: 45.58 mg kg-1), metham sodium (MS: 53.92 mg kg-1) treatments. MS exhibited comparable effectiveness to MB in controlling Meloidogyne spp. and total nematodes, followed by MI at the tested rate. By contrast, sulfuryl fluoride (SF: 33.04 mg kg-1) and chloroform (CF: 23.68 mg kg-1) showed low efficacy in controlling Fusarium spp., Phytophthora spp., and Meloidogyne spp. MB, MI and MS significantly lowered the abundance of different microbial populations and microbial biomass in soil, whereas SF and CF had limited influence on them compared with the control. Diversity indices in Biolog studies decreased in response to fumigation, but no significant difference was found among treatments in PLFA studies. Principal component and cluster analyses of Biolog and PLFA data sets revealed that MB and MI treatments greatly influenced the soil microbial community functional and structural diversity compared with SF treatment. These results suggest that fumigants with high effectiveness in suppressing soil-borne disease could significantly influence soil microbial community.
Topics: Animals; Biodiversity; Biomass; Cluster Analysis; Fumigation; Hydrocarbons, Brominated; Microbial Viability; Microbiota; Nematoda; Soil; Soil Microbiology
PubMed: 25723395
DOI: 10.1371/journal.pone.0117980 -
Journal of Pest Science 2015Live organisms intercepted from treated commodities during phytosanitary inspections usually arouse suspicions of treatment failure, sub-standard treatment application,...
Live organisms intercepted from treated commodities during phytosanitary inspections usually arouse suspicions of treatment failure, sub-standard treatment application, or post-treatment infestation. The additional possibility that some treatments could kill slowly, meaning commodities might be inspected before pests have succumbed, is seldom considered for treatments other than irradiation. We used a novel biochemical viability assay to measure delays between methyl bromide fumigation and mortality of dipteran eggs, and evaluated the correspondence between egg viability and egg morphological features. Our experimental conditions simulated shipping of rock melons from Australia to New Zealand by sea and air. No eggs survived fumigation, but they took 3-20 days to die, whereas phytosanitary inspections of rock melons occur within 2-7 days. Delays were not influenced by methyl bromide concentration, but were significantly lengthened by cooler storage temperatures. Methyl bromide's preservative effects delayed degradation of egg morphology, so the biochemical assay detected mortality long before morphological signs of egg death appeared. The results show that commodities subjected to effective methyl bromide treatments are at risk of being inspected before all pests have either died, or started to exhibit morphological signs of death. This could cause commodities to be unnecessarily rejected by quarantine authorities. Better methods than inspection for live pests are needed to assist authorities to gain assurance that treated commodities have been effectively disinfested. These could be developed by exploiting biochemical responses of pests and commodities to treatments.
PubMed: 25729342
DOI: 10.1007/s10340-014-0573-7 -
Phytopathology Feb 2018Plant pathogens migrate to new regions through human activities such as trade, where they may establish themselves and cause disease on agriculturally important crops.... (Review)
Review
Plant pathogens migrate to new regions through human activities such as trade, where they may establish themselves and cause disease on agriculturally important crops. Verticillium wilt of lettuce, caused by Verticillium dahliae, is a soilborne fungus that was introduced to coastal California via infested spinach seeds. It has caused significant losses for lettuce growers. Once introduced, Verticillium wilt could be managed by fumigating with methyl bromide and chloropicrin, but this option is no longer available. Growers can also manage the disease by planting broccoli or not planting spinach. These control options require long-term investments for future gain. Verticillium wilt can also be prevented or controlled by testing and providing spinach seeds with little or no V. dahliae infestation. However, seed companies have been reluctant to test or clean spinach seeds, as spinach crops are not affected by Verticillium wilt. Thus, available control options are affected by externalities. Renters and other producers with short time horizons will not undertake long-term investments and seed companies do not take into account the effect of their decision not to test on lettuce producers. We review the literature on the economics of managing crop disease; discuss the economics of managing Verticillium wilt; and review the recent research on the externalities that arise with short-term growers, and between seed companies and growers due to Verticillium wilt. An externality arises whenever the actions of one individual or firm affects the payoffs to another individual or firm not involved in a specific transaction. These externalities have important implications for the management of Verticillium wilt and, more broadly, for the management of migratory pathogens and the diseases they cause in agriculture in general. This review is of interest to policy-makers, the producers, marketers, seed companies, and researchers.
Topics: Agriculture; California; Lactuca; Plant Diseases; Seeds; Spinacia oleracea; Verticillium
PubMed: 28703041
DOI: 10.1094/PHYTO-03-17-0083-RVW -
Journal of Environmental Management Feb 2019The effect of sporicidal fumigation with methyl bromide or methyl iodide on the functionality of valuable electronic equipment was evaluated using desktop computers as...
The effect of sporicidal fumigation with methyl bromide or methyl iodide on the functionality of valuable electronic equipment was evaluated using desktop computers as surrogates under target conditions of 200-250 mg/L fumigant for 48 h at 24-30 °C and 75-85% RH. Methyl iodide fumigation damaged light-emitting diodes and optical films in computer displays that were powered-on during fumigation. After five months of post-fumigation operation, five out of six methyl-bromide-fumigated and all six methyl-iodide-fumigated DVD ± RW optical drives failed. Deterioration of rubber spacers critical to maintaining correct disc geometry caused the failure. Metal coupons, included to measure corrosion, showed no significant differences in weight gain between control and fumigation conditions. Relative humidity sensors exhibited a substantial and sometimes irreversible reduction in sensitivity during and after methyl iodide fumigation. Methyl bromide and methyl iodide can cause damage to electronic equipment, but damage seems to be limited to organic materials rather than corrosion of metal surfaces.
Topics: Fumigation; Hydrocarbons, Brominated; Hydrocarbons, Iodinated
PubMed: 30602226
DOI: 10.1016/j.jenvman.2018.10.118